The present invention relates to an apparatus for transmitting an energetic beam, and more particularly a laser beam, which not only makes it possible to bring said beam on to any point of a member on which working is taking place, but also into all points of a cell within which said apparatus is located whilst, if desired, giving thereto a random inclination with respect to the member being worked. More specifically, the invention makes it possible to bring a laser beam into any point located within a spherical zone, whose radius is equal to the length of the apparatus.
Several apparatus types exist, which make it possible to transmit a laser beam to several points. For example, certain of these apparatus make it possible to bring and focus a fixed beam on to a table performing two horizontal movements in perpendicular directions, the table or apparatus making it possible to focus the beam performing a vertical movement.
Other apparatus combine rotational movements, e.g. the rotation of the mirror reflecting the beam and the rotation of the member on which working is taking place. This latter apparatus is more particularly used in the welding of circular parts.
Other systems use hollow cylindrical arms connected by articulations, having mirrors which can deflect the beam. Such a system is described in British Pat. No. 1 215 714, which relates to an apparatus making it possible to deflect a laser beam, by means of one or more mirrors, and to focus it on to the part being worked. One of the variants uses an articulation making it possible to connect two tubes in which the beam is propagated. The end of each of the tubes is curved at right angles and has a mirror inclined by 45.degree. relative to the optical axis of the beam. At the junction of the two tubes, there is a ball-bearing system enabling one of these to perform a rotary movement with respect to the other, the rotation axis coinciding with the optical axis of that part of the laser beam located between these two mirrors.
U.S. Pat. No. 3,528,424 describes an apparatus which can be used in surgery and which has a plurality of arms articulated relative to one another and along which passes a laser beam used for cauterizing wounds.
Although all these systems make it possible to deflect a laser beam, they still have a certain number of disadvantages. Thus, in the case of British Pat. No. 1 215 714, the possibilities of movements are limited and they do not make it possible to reach all points of the volume contained in a sphere, within which is positioned the apparatus. Moreover, in the case of British Pat. No. 1 215 714, the positioning of the articulation between two tubes is liable to bring about an overhang, which could cause deformations of one of the tubes and the optical axis of the laser beam would not then coincide with the geometrical axis of the tube. This defect also occurs with the system described in U.S. Pat. No. 3,528,424 and does not permit a robotization of the apparatus.